A Rasch analysis of the Stanford Hypnotic Susceptibility Scale, Form C.

The psychometric structure of the Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C) was tested in a Rasch analysis using data from 279 subjects. The Rasch model is the model of choice because it justifies the use of the sum of the item scores as a measure for the underlying construct. Rasch analysis revealed that use of a single sum score (number of suggestions passed) to express hypnotic ability is not sufficiently justified. However, the omission of the mosquito-hallucination and anosmia items (Items 3 and 9) rendered this short 10-item form of the SHSS:C sufficiently compatible with requirements of one-dimensionality, local stochastic independence,and equi-discriminability. Hence, the 10-item form justifies use of a sum score.

A randomized controlled clinical trial of a hypnosis-based treatment for patients with conversion disorder, motor type.

This study tested whether a hypnosis-based intervention showed promise as a treatment for patients with conversion disorder, motor type. Forty-four outpatients with conversion disorder, motor type, or somatization disorder with motor conversion symptoms, were randomly assigned to a hypnosis or a waiting-list condition. The hypnosis-condition patients were more improved relative to baseline and the waiting-list controls. Improvement was evident on an observational index of behavioral symptoms associated with the motor conversion and on an interview measure of extent of motor disability. No effect was obtained on a nonspecific measure of broad psychopathology immediately posttreatment. At 6-month follow-up, improvement was maintained across the behavioral and interview measures. The effect size of hypnotizability as a predictor of treatment outcome was comparable to that found for other individual patient differences associated with psychotherapy outcome although non-significant. Hypnotizability scored above patient expectations as a predictor of treatment outcome.

Childhood abuse in patients with conversion disorder.

OBJECTIVE: Despite the fact that the assumption of a relationship between conversion disorder and childhood traumatization has a long history, there is little empirical evidence to support this premise. The present study examined this relation and investigated whether hypnotic susceptibility mediates the relation between trauma and conversion symptoms, as suggested by Janet's autohypnosis theory of conversion disorder. METHOD: A total of 54 patients with conversion disorder and 50 matched comparison patients with an affective disorder were administered the Structured Trauma Interview as well as measures of cognitive (Dissociative Experiences Scale) and somatoform (20-item Somatoform Dissociation Questionnaire) dissociative experiences. RESULTS: Patients with conversion disorder reported a higher incidence of physical/sexual abuse, a larger number of different types of physical abuse, sexual abuse of longer duration, and incestuous experiences more often than comparison patients. In addition, within the group of patients with conversion disorder, parental dysfunction by the mother-not the father-was associated with higher scores on the Dissociative Experiences Scale and the Somatoform Dissociation Questionnaire. Physical abuse was associated with a larger number of conversion symptoms (Structured Clinical Interview for DSM-IV Axis I Disorders). Hypnotic susceptibility proved to partially mediate the relation between physical abuse and conversion symptoms. CONCLUSIONS: The present results provide evidence of a relationship between childhood traumatization and conversion disorder.

Hypnotic susceptibility in patients with conversion disorder.

Conversion disorder has been associated with hypnotic susceptibility for over a century and is currently still believed to be a form of autohypnosis. There is, however, little empirical evidence for the relation between hypnotic susceptibility and conversion symptoms. The authors compared 50 patients with conversion disorder with 50 matched control patients with an affective disorder on measures of hypnotic susceptibility, cognitive dissociation, and somatoform dissociation. Conversion patients were significantly more responsive to hypnotic suggestions than control patients. In addition, conversion patients showed a significant correlation between hypnotic susceptibility and the number of conversion complaints. These results provide the first evidence of a relationship between hypnotic susceptibility and the presence and number of conversion symptoms.

A randomised controlled clinical trial on the additional effect of hypnosis in a comprehensive treatment programme for in-patients with conversion disorder of the motor type.

BACKGROUND: The primary aim of this study was threefold: (1) to examine the additional effects of hypnosis aimed at symptom reduction, using symptom-oriented and expression- and insight-oriented techniques in a comprehensive clinical treatment programme for in-patients with a persistent conversion disorder of the motor type; (2) to assess whether the level of hypnotisability was predictive of treatment outcome, and (3) to explore the efficacy of the total clinical treatment programme. METHODS: The study population consisted of 45 in-patients between 18 and 65 years of age meeting the DSM-III-R criteria for conversion disorder of the motor type or somatisation disorder with motor conversion symptoms. A randomised controlled clinical trial was undertaken. The primary outcome measures were the Video Rating Scale for Motor Conversion Symptoms, the D(isabilities) code items from the International Classification of Impairments, Disabilities and Handicaps and the Symptom Checklist-90. Measures of the credibility of treatment and patient expectations of treatment outcome were used as manipulation checks. Hypnotisability was measured using the Stanford Hypnotic Clinical Scale. RESULTS: Significant treatment results for all outcome measures were found for the total sample. These effects proved to be clinically significant. The use of hypnosis had no additional effect on treatment outcome. Hypnotisability was not predictive of treatment outcome. CONCLUSION: A comprehensive treatment programme, either with or without hypnosis, can be worthwhile for patients with long-standing conversion symptoms.

Motor imagery during hypnotic arm paralysis in high and low hypnotizable subjects.

Previous research suggests that conversion disordered patients with hand/arm paralysis exhibit slowed reaction times for mental hand-rotation tasks that correspond to their affected arm when the tasks are explicitly instructed and not when they are implicitly cued. Because of the many similarities between hypnotic phenomena and conversion symptoms, the authors tested whether similar motor imagery impairment would occur among normal high hypnotizable subjects when paralysis is suggested. Nine high and 8 low hypnotizable subjects were administered an implicit and an explicit mental hand-rotation task during hypnotically suggested paralysis of the right arm. On the implicit task, there were no significant reaction time (RT) differences between highs and lows. On the explicit task, only highs showed a significantly larger RT increase per degree of rotation with the paralyzed arm, compared to the normal arm. These preliminary findings suggest that the motor imagery impairment observed in conversion paralysis can be induced in highs using hypnosis.